Delivery-pipe for hydraulic dredging-machines.



A. W. ROBINSON.

DELIVERY PIPE FOR HYDRAULIC DREDGING MACHINES.

APPLICATION FILED DEC. I2, 1917.

Patented m. '24, 1918.

DELIVERY-PIPE FOR HYDRAULIC DREDGING-MACHINES.

Application filed December 12, 1917.

To all whom it may concern:

Be it known that I, ARTHUR W. ROBIN- soN, a citizen of the Dominion of Canada, and a resident of the city of Montreal, county of Hochelaga, Province of Quebec, and Dominion of Canada, have invented a new and useful improvement in deliverypipes for hydraulic dredging-machines of the class in which the spoils, consisting of earth, clay, sand, gravel, etc., is transported from the dredging-machine or other source of supply to the place of deposit by being pumped through a delivery-pipe together with a suitable admixture of water.

The invention accomplishes several desirable results:

First: It reduces the wear on the interior of the delivery pipe due to the gritty material being carried at necessarily high velocity;

Second: It prevents the settling or deposit of solid matter, such as sand, gravel or stone, in the bottom of the pipe;

Third: It increases the carrying capacity of the pipe, so that more solid matter can be transported at a given velocity, or an equal amount at a less velocity; thus further reducing the wear and better utilizing the power necessary to drive the pump.

There are other incidental advantages which will be appreciated by those familiar with this art by the following description.

Certain modified forms in which my invention may be embodied are shown in the accompanying drawings. They are, however, by no means the only constructions which may be adopted.

In the drawings Figure 1 is a cross section of a cylindrical pipe embodying one form of my invention; Fig. 2 is a longitudinal section, a part being shown in elevation, of the form of my invention shown in Fig. 1; Fig. 3 is a perspective view of a modified construction in which a bottom liner plate only is employed and it is made of wood instead of metal; Fig. 4 is a sectional view, somewhat enlarged, of the form shown in Figs. 1 and 2, and illustrating a detail of construction; Fig. 5 is a modification of the construction shown in Fig. 3.

Referring to the drawings, 1 represents the delivery pipe. It is preferably made of metal, cast or wrought, as the case may be, and of the usual construction and provided with the usual fittings; 2 is a flat liner plate located in the top of the pipe; 3 is a similar Specification of Letters Patent.

Patented Dec. 24, 1918.

Serial No. 206,815.

flat liner plate located in the bottom of the pipe. These liner plates may be of such material as preferred. In Figs. 1, 2 and 4, they are illustrated as steel plates of such length as preferred, and in Figs. 3 and 5, they are shown as made of wood.

The plates may be held in place within the pipe in any preferred manner. In Figs. 1, 2 and 4, I show them held by bolts 4, the nuts 5 being upon the outside of the pipe. As a matter of convenience I prefer to make the bolts as shown in Fig. 4, that is to say, I curve the shank of the bolt, as shown, to such degree as may be necessary to properly present the head of the bolt to the liner plate with which it engages, and that the other or threaded end of the bolt may be properly presented to the exterior surface of the delivery pipe, so that the nut may take a proper and mechanical bearing thereon.

' The Wooden or timber liner plates shown in Figs. 3 and 5 may be held in place by bolts such as shown in the other figures of the drawing, or otherwise, as preferred; but I have found it desirable to modify the construction where wooden liners are employed,

particularly if a bottom liner only is presso that the wooden liners 3 will be held in position by these angle irons overlapping them at each edge, thus preventing any upward movement, and the rounding contourof the inner surface of the pipe against which they rest, prevents any downward movement. This construction has the advantage that when wooden liners shall become worn out, new ones can be readily introduced by disconnecting the delivery pipe and withdrawing from each section the worn out wooden liner and substituting a new one by simply properly fashioning the edge of the plank or timber and sliding it into the pipe beneath the ledge or bracket 6; the ends of the plank having been suitably squared, will abut against each other. Therefore practically any length of planking may be used for relining the pipe.

In order to avoid the necessity for specially forming the angle irons 6 for this special use, I sometimes modify the construction as shown in Fig. 5, so that the ordinary rectangular angle irons can be used, such as shown at 8 in Fig. 5. In this case it is desirable to chamfer off the edges of the plank, as shown at 9, to roughly at least coincide with the angles of the metal surfaces against which it rests. It will be understood, of course, that it is not essential that the ledges or angle irons 6 and 8 shall be continuous throughout the entire length of each section of the delivery pipe, because suitably located lengths of such ledges or bracket-like material may be employed, thus effecting a saving in the cost and weight; but it will be noted that if the angle iron be continuous, that then the joint between the liner plate and the pipe is additionally protected against wear because of the presence of the continuous angle irons.

If steel or metallic liner plates be employed, it is an easy matter to substitute new ones for those which have become worn out by simply disconnecting the various pipe sections, unscrewing the nuts 5 and knocking back the bolts 4:, whereupon the plates will become loose within the pipe and may be readily removed and other ones substituted.

The operation is as follows:

The action of a flow of a mixture of water and dredged material in a pipe having a flattened interior produced by the interior liner plates above described is essentially different from that in the usual round or cylindrical pipes, because in the latter it is found that even at high velocities, the water in the upper portion of the pipe is practically clear, unless the dredged material be mud or clay, and that in any event the heavier dredgings, which contain practically all of the solid matter, requiring power for its delivery, rests upon and is moved along thebottom of the pipe, so that the heavier stuff, such as gravel and cobbles, tend to lodge, and becoming jammed at the bottom of the pipe, resist the onward thrust of the water, requiring increase of power on the part of the pump to dislodge them, and

, sometimes effecting a clogging of the pipe altogether, thus requiring stoppage in the work, disconnection of the pipe sections, cleansing, etc., and this clogging action is facilitated and induced by the sloping sides of the bottom of the pipe down which the heavier material works its way and is aided in its'desire to lodge because of the skin friction, and also because of the gradually contracting area of the bottom are of the pipe. My invention, therefore, is a very great improvement in such mechanism because the carrying of detritus hydraulically is much more efficiently performed on a Hat surface, as in the bed of a stream and in a sluice, used for hydraulic mining, than in a concave pipe bottom as heretofore used. Where the bottom of the pipe presents a flat surface the material has no opportunity to jam each particle against its neighbors, thus resisting the onward flow; on the contrary, the water sweeping with equal force over the entire bottom, rolls the reluctant heavier material along with little probability that it will am or key itself together; thus the car rying capacity is increased, the necessary pump power reduced and the liability to choke removed.

The liner at the top of the pipe serves also a very important office, that is to say, it prevents the water from separating from the detritus under the action of gravity and flowing as a practically clear stream in the upper part of the pipe, for it holds the water down to its work, compelling it, or at least most of it, to carry its due proportion of the-load. It istrue that the interposition of the liners, one or both, just so much restricts the effective water bearingvarea of the pipe and it may be suggested that the pipes will for the same amount of work have to be correspondingly enlarged; but

this is not the fact, quite the contrary; be-

cause, for reasons fully explained above, the

upper arc and also the lower arc of the interior of cylindrical pipes as heretofore used the efiective work is done within the area inclosed betweenmy new liner plates. Therefore there'is a marked economy realized by the use of my invention, since while the cy lindrical form of the pipe is retained, which is necessary on the score of strength and economy, all of the power of the pump is employed for the projection of the detritus and none of it is wasted in idly pumping water, nor is any time lost in disconnecting the pipe sections, for the'removal of lodged deposits; and in addition to this, the life of the pipe itself is materially extended, because the wear comes almost entirely upon the relatively inexpensive and easily renewed bottom liner plate.

It will be obvious to those who are familiar with such matters that modifications other than those illustrated and described may be adopted and yet the essentials of the invention be retained. I therefore do not limit myself to such details.

I claim: p

1. A longitudinally cylindrical metallic delivery pipe for hydraulic dredging apparatus having a flat interior lower surface located at about the lower fourth of the interior diameter of the pipe and extending from side to side of the curved interior surface thereto. 7

2. A longitudinally cylindrical. metallic delivery pipe for hydraulic-dredging apparatus having flat interior upper and lower surfaces, the former being located at about the upper fourth and the latter at about the lower fourth of the interior diameter of the pipe and extending from side to side of the curved surface thereof.

3. A longitudinally cylindrical metallic delivery pipe for hydraulically transporting solid matter and Water having opposite disposed ledges on its interior surface and a Copies of this patent may be obtained for five cents each, by addressing the longitudinally extending and independent fiat bottom lining located at about the lower fourth of the interior diameter of the pipe and extending from side to side of the curved surface thereof and supported upon the said oppositely disposed ledges.

In testimony whereof I have signed my name to this specification.

ARTHUR W. ROBINSON.

Commissioner of Patents,

Washington, D. 0. 

